Re: [PATCH] dt-bindings: memory: renesas,rpc-if: Document R-Car V4H support

From: Geert Uytterhoeven
Date: Thu Oct 13 2022 - 04:24:38 EST

Hi Wolfram,

On Thu, Oct 13, 2022 at 10:00 AM Wolfram Sang
<wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote:
> > I actually wrote such a patch a while back.
> > However, I didn't send it after discovering the R-Car V3U Series
> > User’s Manual Rev. 0.50 does not mention the fourth Strobe Timing
> > Adjustment bit (STRTIM) in the RPC-IF PHY Control Register (PHYCNT),
> > which is present on R-Car S4-8 and V4H, but not on R-Car Gen3.
> I see. Thanks for the heads up! Maybe this is worth a comment because it
> is an exception to the usual behaviour?

You mean an exception to the exception to the usual behaviour that
R-Car <foo>3 is part of the R-Car Gen3 family, making it the normal
rule? ;-)

We're actually not 100% sure the bit is present or not. Rev. 0.50 is
still an early revision of the R-Car V3U documentation, so it might lack
some updates. I tried changing all bits of the PHYCNT register, but
unfortunately all bits except for bit 31 stick on all SoCs I tried, so
we can't use this method to determine which bits exist and which don't.



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds